Intravesical sequential gemcitabine and docetaxel versus bacillus calmette-guerin (BCG) plus interferon in patients with recurrent non-muscle invasive bladder cancer following a single induction course of BCG

INTRODUCTION

Repeat BCG induction remains an option for select non-muscle invasive bladder cancer (NMIBC) patients who fail initial therapy. Alternative salvage intravesical regimens such as Gemcitabine and Docetaxel (Gem/Doce) have been investigated. We aimed to compare the efficacy BCG plus interferon a-2b (BCG/IFN) and Gem/Doce in patients with recurrent NMIBC after a single prior BCG course.

METHODS

The National Phase II BCG/IFN trial database and multi-institutional Gem/Doce database were queried for patients with recurrent NMIBC after one prior BCG induction course, excluding those with BCG unresponsive disease. Stabilized inverse probability treatment weighted survival curves were estimated using the Kaplan-Meier method and compared. Propensity scores were derived from a logistic regression model. The primary outcome was recurrence free survival (RFS); secondary outcomes were high-grade (HG) RFS and risk factors for treatment failure.

RESULTS

We identified 197 BCG/IFN and 93 Gem/Doce patients who met study criteria. Patients receiving Gem/Doce were older and more likely to have HG disease, CIS, and persistent disease following induction BCG (all P < 0.01). After propensity score-based weighting, the adjusted 1- and 2-year RFS was 61% and 53% after BCG/IFN versus 68% and 46% after Gem/Doce (P = 0.95). Adjusted 1- and 2-year HG-RFS was 60% and 51% after BCG/IFN versus 63% and 42% after Gem/Doce (P = 0.68). Multivariable Cox regression revealed that Gem/Doce treatment was not associated with an increased risk of failure (HR = 0.97, P = 0.89) as compared to BCG/IFN.

CONCLUSION

Patients with recurrent NMIBC after a single induction BCG failure and not deemed BCG unresponsive had similar oncologic outcomes with Gem/Doce and BCG/IFN in a post-hoc analysis. Additional prospective studies are needed.

Comparison of Major Complications at 30 and 90 Days Following Radical Cystectomy

OBJECTIVES

To better understand the time-course in which major complications occur after radical cystectomy and to describe associations with complications at 30 and 90 days.

METHODS

A database of radical cystectomy cases was queried for preoperative, perioperative, and postoperative data. Follow-up extended to 90 days postsurgery and included major complications (Clavien III-V). Early (30-day) and late (90-day) complication rates were compared via McNemar's test, and patient characteristics were compared across complication time groups by one-way ANOVA or Fisher's exact tests. Multinomial logistic regression was used to explore associations between patient characteristics and complication timing.

RESULTS

Of 969 patients undergoing radical cystectomy, 210/969 (21.7%) experienced a complication within 90 days. The rate of major complication significantly differed at 30 and 90 days (14.4% [conflict of interest (CI): 12.4%-16.9%] vs 21.7% [CI: 19.2%-24.4%] respectively, P ≤.0001). Chronic obstructive pulmonary disease (COPD) (P = .03), Charlson Comorbidity Index (P = .02), and Indiana pouch diversion (P = .002) were significant predictors of early complication. Diabetes was the strongest predictor for late complication (OR: 2.42; P = 0.01). Diabetes was also a significant predictor for late genitourinary complications (OR 3.39; P = .01), and smoking history was a significant predictor for late infectious complications (OR 3.61; P = .01).

CONCLUSION

We identified a significant number of complications occurring after 30 days postcystectomy, including the majority of deaths and genitourinary complications. These findings suggest that assessment of complications exclusively at 30 days would fail to capture a large proportion of major complications and deaths. Understanding the time-course of complications postcystectomy will serve to better inform design of future outcome studies.

Uretero-Enteric Anastomotic Stricture Following Radical Cystectomy: A Comparison of Open, Robotic Extracorporeal, and Robotic Intracorporeal Approaches

OBJECTIVES

To compare the incidence of benign uretero-enteric anastomotic strictures between open cystectomy, robotic cystectomy with extracorporeal urinary diversion, and robotic cystectomy with intracorporeal urinary diversion. The effect of surgeon learning curve on stricture incidence following intracorporeal diversion was investigated as a secondary outcome.

PATIENTS AND METHODS

Patients who underwent radical cystectomy at an academic hospital between 2011 and 2018 were retrospectively reviewed. The primary outcome, incidence of anastomotic stricture over time, was assessed by a multivariable Cox proportional hazards regression. A Cox regression model adjusting for sequential case number in a surgeon's experience was used to assess intracorporeal learning curve.

RESULTS

Nine hundred sixty-eight patients were included: 279 open, 382 robotic extracorporeal, and 307 robotic intracorporeal. Benign stricture incidence was 11.3% overall: 26 (9.3%) after open, 43 (11.3%) after robotic extracorporeal, and 40 (13.0%) after robotic intracorporeal. An intracorporeal approach was associated with anastomotic stricture on multivariable analysis (HR 1.66; P = .05). After 75 intracorporeal cases, stricture incidence declined from 17.5% to 4.9%. Higher sequential case volume was independently associated with reduced stricture incidence (Hazard Ratio per 10 cases: 0.90; P = .02).

CONCLUSION

An intracorporeal approach to urinary reconstruction following robotic radical cystectomy was associated with an increased risk of benign uretero-enteric anastomotic stricture. In surgeons' early experience with intracorporeal diversion the difference in stricture incidence was more pronounced compared to alternative approaches; however, increased intracorporeal case volume was associated with a decline in stricture incidence leading to a modest difference between the 3 surgical approaches overall.

Obesity induces limited changes to systemic and local immune profiles in treatment-naive human clear cell renal cell carcinoma

Understanding the effects of obesity on the immune profile of renal cell carcinoma (RCC) patients is critical, given the rising use of immunotherapies to treat advanced disease and recent reports of differential cancer immunotherapy outcomes with obesity. Here, we evaluated multiple immune parameters at the genetic, soluble protein, and cellular levels in peripheral blood and renal tumors from treatment-naive clear cell RCC (ccRCC) subjects (n = 69), to better understand the effects of host obesity (Body Mass Index "BMI" ≥ 30 kg/m2) in the absence of immunotherapy. Tumor-free donors (n = 38) with or without obesity were used as controls. In our ccRCC cohort, increasing BMI was associated with decreased percentages of circulating activated PD-1+CD8+ T cells, CD14+CD16neg classical monocytes, and Foxp3+ regulatory T cells (Tregs). Only CD14+CD16neg classical monocytes and Tregs were reduced when obesity was examined as a categorical variable. Obesity did not alter the percentages of circulating IFNγ+ CD8 T cells or IFNγ+, IL-4+, or IL-17A+ CD4 T cells in ccRCC subjects. Of 38 plasma proteins analyzed, six (CCL3, IL-1β, IL-1RA, IL-10, IL-17, and TNFα) were upregulated specifically in ccRCC subjects with obesity versus tumor-free controls with obesity. IGFBP-1 was uniquely decreased in ccRCC subjects with obesity versus non-obese ccRCC subjects. Immunogenetic profiling of ccRCC tumors revealed that 93% of examined genes were equivalently expressed and no changes in cell type scores were found in stage-matched tumors from obesity category II/III versus normal weight (BMI ≥ 35 kg/m2 versus 18.5-24.9 kg/m2, respectively) subjects. Intratumoral PLGF and VEGF-A proteins were elevated in ccRCC subjects with obesity. Thus, in ccRCC patients with localized disease, obesity is not associated with widespread detrimental alterations in systemic or intratumoral immune profiles. The effects of combined obesity and immunotherapy administration on immune parameters remains to be determined.

Multi-Institution Evaluation of Sequential Gemcitabine and Docetaxel as Rescue Therapy for Nonmuscle Invasive Bladder Cancer

PURPOSE

Rescue intravesical therapies for patients with bacillus Calmette-Guérin failure nonmuscle invasive bladder cancer remain a critical focus of ongoing research. Sequential intravesical gemcitabine and docetaxel therapy has shown safety and efficacy in 2 retrospective, single institution cohorts. This doublet has since been adopted as an intravesical salvage option at multiple institutions. We report the results of a multi-institutional evaluation of gemcitabine and docetaxel.

MATERIALS AND METHODS

Each institution retrospectively reviewed all records of patients treated with intravesical gemcitabine and docetaxel for nonmuscle invasive bladder cancer between June 2009 and May 2018. Only patients with recurrent nonmuscle invasive bladder cancer and a history of bacillus Calmette-Guérin treatment were included in the analysis. If patients were disease-free after induction, maintenance was instituted at the treating physician's discretion. Posttreatment surveillance followed American Urological Association guidelines. Survival analysis was performed using the Kaplan-Meier method and risk factors for treatment failure were assessed with Cox regression models.

RESULTS

Overall 276 patients (median age 73 years, median followup 22.9 months) received treatment. Nine patients were unable to tolerate a full induction course. One and 2-year recurrence-free survival rates were 60% and 46%, and high grade recurrence-free survival rates were 65% and 52%, respectively. Ten patients (3.6%) had disease progression on transurethral resection. Forty-three patients (15.6%) went on to cystectomy (median 11.3 months from induction), of whom 11 (4.0%) had progression to muscle invasion. Analysis identified no patient, disease or prior treatment related factors associated with gemcitabine and docetaxel failure.

CONCLUSIONS

Intravesical gemcitabine and docetaxel therapy is well tolerated and effective, providing a durable response in patients with recurrent nonmuscle invasive bladder cancer after bacillus Calmette-Guérin therapy. Further prospective study is warranted.

Neurogenic bladder monitoring using the cystomanometer and cystoelastometer

INTRODUCTION

Patients with neurogenic bladder (NGB) require periodic urodynamics (UDS) to evaluate bladder function, which in turn helps guide management. At times, bladder decompensation or hydronephrosis may develop in patients between urodynamic testing intervals. Increased surveillance has improved outcomes in other chronic conditions (e.g., diabetes). Two novel devices, the cystomanometer (CM) and cystoelastometer (CEM), have been developed at the authors' institution to allow for home bladder pressure monitoring. The handheld CM can be attached to the end of any catheter and records the opening bladder pressure along with a time stamp. In addition, the CEM actively evacuates urine via a pump and records the urine volume evacuated. For safety, the pump slows and stops as it detects increasing resistance. Data are stored and transmitted wirelessly from both devices to a smartphone. A novel phone application stores, displays, and transmits data to a secure hospital server.

OBJECTIVE

This aim of this study was to validate the function of the CM and CEM and their accuracy relative to UDS.

STUDY DESIGN

Institutional review board approval was obtained. All patients with NGB managed with intermittent catheterization undergoing routine UDS were eligible for study inclusion. At the completion of UDS, the instillation port of the 6-French dual-lumen UDS catheter was connected to the CM or CEM. Bladder parameters were simultaneously recorded using the device and UDS during bladder emptying. Correlative statistics were calculated.

RESULTS

A total of 36 patients (30 children/6 adults; age range from 1.2 to 38 years [median: 7.5 years]) underwent CM testing. Strong pressure correlation with UDS was identified (R² = 0.89). A total of 42 patients (30 children/12 adults; age range of 2.9-85.2 years [median: 12.2 years]) underwent CEM testing. Again, strong pressure correlation was found (R² = 0.77). Cystoelastometer volume measurements were highly correlated with measured volumes (Fig. 4, R² = 0.98).

DISCUSSION

Both the CM and CEM functioned well and transmitted the data wirelessly to a smartphone. The data from these devices were strongly correlated with simultaneous data from the UDS. A limitation is that these devices were used by healthcare providers, and therefore, use by patients or their parents/caregivers at home has not been demonstrated.

CONCLUSION

The CM and CEM devices provide accurate bladder pressure and volume measurements. The potential for improved patient monitoring and care is promising. Reliability testing and the effects of such monitoring on patient outcomes remain to be determined.

Quadruple immunotherapy of Bacillus Calmette-Guérin, interferon, interleukin-2, and granulocyte-macrophage colony-stimulating factor as salvage therapy for non-muscle-invasive bladder cancer

BACKGROUND

Bacillus Calmette-Guérin (BCG) is the most effective initial intravesical therapy for high-grade non-muscle invasive bladder cancer, but many patients still fail. Combination intravesical BCG and interferon (IFN) will salvage some patients but results remain suboptimal.

OBJECTIVE

We hypothesized that further immunostimulation with intravesical interleukin-2 and subcutaneous granulocyte-macrophage colony-stimulating factor may improve response to intravesical BCG and IFN in patient with prior BCG failure(s).

METHODS

A retrospective review was performed. Patients received 6 treatments of quadruple immunotherapy (intravesical solution with one-third dose BCG, 50 million units IFN, and 22 million units interleukin-2, along with a 250-mcg subcutaneous sargramostim injection). Surveillance began 4 to 6 weeks after treatment completion. Patients received maintenance if recurrence-free. Success was defined as no recurrence (bladder or extravesical) and bladder preservation. Analysis was performed by Kaplan-Meier method (P<0.05).

RESULTS

Fifty-two patients received treatment with a median recurrence follow-up of 16.3 months and overall follow-up of 41.8 months. All patients had at least 1 prior BCG failure and 13% had 2 or more prior failures. Only 3 patients (6%) were unable to tolerate full induction. Treatment success was 55% at 1 year, and 53% at 2 years. Thirteen patients (25%) underwent cystectomy at a median time of 17.3 months with disease progression to T2 in 1 patient and T3 in 2 patients. No patients had positive surgical margins or positive lymph nodes.

CONCLUSIONS

In patients with non-muscle-invasive bladder cancer with prior BCG failure, quadruple immunotherapy demonstrated good treatment success in some patients and warrants further evaluation.

Obesity as defined by waist circumference but not body mass index is associated with higher renal mass complexity

OBJECTIVES

Obesity, typically defined as a body mass index (BMI)≥30kg/m², is an established risk factor for renal cell carcinoma (RCC) but is paradoxically linked to less advanced disease at diagnosis and improved outcomes. However, BMI has inherent flaws, and alternate obesity-defining metrics that emphasize abdominal fat are available. We investigated 3 obesity-defining metrics, to better examine the associations of abdominal fat vs. generalized obesity with renal tumor stage, grade, or R.E.N.A.L. nephrometry score.

METHODS AND MATERIALS

In a prospective cohort of 99 subjects with renal masses undergoing resection and no evidence of metastatic disease, obesity was assessed using 3 metrics: body mass index (BMI), radiographic waist circumference (WC), and retrorenal fat (RRF) pad distance. R.E.N.A.L. nephrometry scores were calculated based on preoperative CT or MRI. Univariate and multivariate analyses were performed to identify associations between obesity metrics and nephrometry score, tumor grade, and tumor stage.

RESULTS

In the 99 subjects, surgery was partial nephrectomy in 51 and radical nephrectomy in 48. Pathology showed benign masses in 11 and RCC in 88 (of which 20 had stage T3 disease). WC was positively correlated with nephrometry score, even after controlling for age, sex, race, and diabetes status (P = 0.02), whereas BMI and RRF were not (P = 0.13, and P = 0.57, respectively). WC in stage T2/T3 subjects was higher than in subjects with benign masses (P = 0.03). In contrast, subjects with Fuhrman grade 1 and 2 tumors had higher BMI (P<0.01) and WC (P = 0.04) than subjects with grade 3 and 4 tumors.

CONCLUSIONS

Our data suggest that obesity measured by WC, but not BMI or RRF, is associated with increased renal mass complexity. Tumor Fuhrman grade exhibited a different trend, with both high WC and BMI associated with lower-grade tumors. Our findings indicate that WC and BMI are not interchangeable obesity metrics. Further evaluation of RCC-specific outcomes using WC vs. BMI is warranted to better understand the complex relationship between general vs. abdominal obesity and RCC characteristics.

Obesity-induced changes to the immune landscape in human renal cell carcinoma subjects

Immunotherapy for advanced renal cell carcinoma (RCC) has shown tremendous promise. However, clinical responses remain &lt;30% and the reasons are unclear. Obesity affects ~35% of U.S. adults and is a major risk factor for RCC. We reported previously that obesity impairs immunotherapeutic efficacy in a murine renal cancer model, due to increased myeloid suppressor cells and weakened effector CD8 T cell responses. Based on these results, we hypothesized that obesity would also induce detrimental shifts in the immune landscape in treatment-naive subjects with confirmed RCC. In an IRB-approved study, we consented 86 RCC subjects with obesity (mean BMI = 38.4) and 77 normal to over-weight RCC subjects (mean BMI = 25.0), plus tumor-free controls, into a prospective study to examine intra-tumoral and systemic leukocytes by multi-parameter flow cytometry, plasma proteins via multiplex, and tumor gene expression by Nanostring. Numerous systemic cell populations (ex: CD45RO+ PD1+ CD4 or CD8 T cells, and HLA-DR- CD14− CD11b+MDSC, all p&gt;0.05) were unaltered by obesity in RCC subjects. Peripheral CD14+ inflammatory monocytes and Foxp3+ Tregs were decreased in RCC subjects with obesity (both p&lt; 0.05). However, obesity altered plasma proteins to favor RCC progression, with increased angiopoietin, VEGF-A and –C, and IL-8 (all p&lt; 0.05). Within renal tumors, obesity did not alter CD4 or CD8 T cell percentages or phenotypes (CD45RO, PD1, CD56). Nanostring analysis of renal tumors revealed multiple obesity-related changes in pro-tumorigenic genes. Thus, obesity in RCC subjects had surprisingly few effects on cellular immunity, but multiple effects on protein mediators that may shift the overall immune landscape toward one that favors tumor progression.

Experience with Sequential Intravesical Gemcitabine and Docetaxel as Salvage Therapy for Non-Muscle Invasive Bladder Cancer

Patients with high-grade muscle invasive bladder cancer (NMIBC) receive intravesical therapy with bacillus Calmette-Guérin (BCG) as the well-established standard-of-care. However, even with prompt induction of intravesical therapy, approximately 40 % of patients will recur within 2 years. For patients who fail BCG, options include radical cystectomy, repeat BCG therapy, or alternative intravesical salvage therapy. In this review, we will discuss the most recent published evidence on salvage intravesical therapy with an emphasis on a more in-depth report of our therapeutic strategy with sequential gemcitabine and docetaxel intravesical therapy for this treatment-refractory population. In addition, we will provide practical advice on our approach to this challenging patient population including the use of operative staging to aid early identification of treatment failures.

Bacillus Calmette-Guérin (BCG) Treatment Failures with Non-Muscle Invasive Bladder Cancer: A Data-Driven Definition for BCG Unresponsive Disease

Objective: To create the first data-driven definition for those unlikely to benefit from further BCG treatment.

Materials and Methods: The database created for the Phase 2 BCG-Interferon-α 2B (IFN) study was queried and BCG failure patients were identified (n = 334). Full study protocols have previously been published. Separate models were constructed for analysis of patients with any CIS (pure or concomitant) and pure papillary disease. Variables considered included age, gender, stage, grade, tumor size and focality (for papillary only), number of prior BCG courses, and prior BCG failure interval.

Results: Patients with recurrent CIS within 6 months of their most recent prior BCG course (HR 2.56, p <  0.01) and ≥2 prior BCG failures (HR 1.54, p <  0.01) responded worst to repeat intravesical therapy. Those with CIS recurrence at 6–12 months did not differ from those recurring within 6 months (HR = 0.88, p = 0.71). Patients with recurrent papillary disease within 6 months (HR 1.82, p = 0.02), ≥2 BCG failures (HR 1.54, p = 0.03), and multifocal disease (HR 2.05, p <  0.01) responded worst to therapy. Patients with T1 disease remained disease free in 38% of cases (24–51% 95% CI) at 2 years with low rates of progression.

Conclusions: Patients who fail two courses of BCG with either persistent or recurrent multifocal papillary disease within 6 months or CIS within 12 months of their prior BCG should be considered BCG unresponsive. Recurrent T1 disease respond reasonably well to another course with low progression rates but further investigation is warranted.

Intravesical and alternative bladder-preservation therapies in the management of non-muscle-invasive bladder cancer unresponsive to bacillus Calmette-Guérin

Intravesical Bacillus Calmette-Guérin (BCG) remains the standard of care in the treatment of bladder carcinoma in situ and as adjuvant therapy after thorough transurethral resection of high-grade non-muscle-invasive bladder cancer. Despite BCG therapy, in up to 40% of patients it would recur and 60% to 70% of those would fail repeat BCG induction be deemed BCG unresponsive. For such patients, cystectomy remains the preferred treatment option per the American Urological Association and European Association of Urology, though some patients would be medically unfit or refuse radical surgery. Further intravesical therapy for bladder-preservation therapies may preserve quality of life in these patients and in some cases can be curative. There are numerous non-BCG intravesical salvage options available, including immunotherapy, single-agent chemotherapy, combination chemotherapy, and device-assisted chemotherapy. In addition, investigation of radiation-based treatment and other novel therapies including checkpoint inhibitors (programmed death-1/programmed death ligand-1), are currently underway. In this review, we examine the current status of alternatives to BCG in salvage therapy for bladder preservation.

Bacillus Calmette-Guérin (BCG) Treatment Failures in Non-Muscle Invasive Bladder Cancer: What Truly Constitutes Unresponsive Disease

Bacillus Calmette-Guérin (BCG) remains the most effective intravesical therapy for non-muscle invasive bladder cancer but will fail in up to 40% of patients. The ability to identify patients who are least likely to respond to further BCG therapy allows urologists to pursue secondary treatments more likely to convey a recurrence or survival benefit to the patient. We examined the literature to determine what constitutes BCG unresponsive disease. After review, we believe that BCG unresponsive disease should be defined as (1) patients with recurrent high grade T1 disease within 6 months of their primary tumor after at least one course of BCG or patients who have failed at least 2 courses of BCG with either (2) persistent or recurrent pure papillary (Ta) disease within 6 months or (3) persistent or recurrent carcinoma in situ (CIS) within 12 months.

Sequential Intravesical Gemcitabine and Docetaxel for the Salvage Treatment of Non-Muscle Invasive Bladder Cancer

Background:

Bacillus Calmette-Guerin (BCG) is the most effective intravesical therapy for non-muscle invasive bladder cancer (NMIBC), but patients can fail or supply shortages can develop. For BCG failures, radical cystectomy is recommended. However, in patients who desire bladder preservation or are poor surgical candidates, alternative salvage intravesical therapies should be explored.

Objective:

To determine whether dual sequential intravesical gemcitabine and docetaxel is effective in treating NMIBC.

Methods:

We evaluated our initial experience with 45 patients treated with intravesical gemcitabine and docetaxel between June 2009 and May 2014. Patients were treated with 6 weekly instillations of gemcitabine (1 gram of gemcitabine in 50 ml of sterile water) followed immediately by docetaxel (37.5 mg of docetaxel in 50 mL of saline). Treatment success was defined as no bladder cancer recurrence and no cystectomy. Intention-to-treat analysis was performed using the Kaplan Meier method.

Results:

Forty-five patients received treatment with a median overall follow-up of 15 months. Median follow up for treatment success was 6 months in all patients and 13 months for responders. Five patients were unable to tolerate a full induction course. Treatment success was 66% at first surveillance, 54% at 1 year, and 34% at 2 years after initiating induction. Ten patients received cystectomy (median of 5.6 months from starting induction) with no positive margins or lymph nodes on final pathology.

Conclusions:

Sequential dual intravesical gemcitabine and docetaxel can salvage some patients in a challenging NMIBC cohort.

Application of ultrasound-based velocity estimate statistics to strain-rate estimation

Quantification of the relative myocardial deformation rate, or strain rate, is an emerging capability to aid a cardiologist in assessing myocardial function. Ultrasound Doppler techniques can be used to compute tissue motion relative to a transducer. The myocardial strain rate can be computed as the localized spatial derivative of the tissue velocity. Such a strain-rate estimate is typically numerically noisy. We present the relevant speckle statistics to faciliate the computation of the strain rate based on a weighted least squares regression, with statistically appropriate weights.

Carboxyhemoglobin levels in patients with sickle-cell anemia: relationship to hemolytic and vasoocclusive severity

BACKGROUND

When carbon monoxide binds to hemoglobin, it increases the affinity of hemoglobin for oxygen and shifts the oxygen dissociation curve to the left. The resulting decrease in sickling tendency could have clinical benefit, and carbon monoxide has been suggested as a treatment for sickle-cell disease. Furthermore, in sickle-cell disease, as in other hemolytic diseases, endogenous carbon monoxide production is increased because of increased heme catabolism.

METHODS

In the present study, we measured carboxyhemoglobin levels in sickle-cell patients and compared them with estimates of the hemolytic and the vasoocclusive severity of the disease.

RESULTS

Significant correlation was found between carboxyhemoglobin (HbCO) levels and hematocrit, reticulocyte count, unconjugated bilirubin level, and percentage of irreversibly sickled cells. However, there was no significant correlation between carboxyhemoglobin levels and measures of the vaso-occlusive severity of the disease.

CONCLUSIONS

The correlations between HbCO levels and measures of hemolytic severity are best explained by the known relationship between hemoglobin catabolism and CO production. The lack of correlation with vaso-occlusive severity may be due to the complex changes involved and the difficulty of quantifying vasoocclusive severity.

Digoxin to facilitate late second-trimester abortion: a randomized, masked, placebo-controlled trial

OBJECTIVE

To examine the efficacy of digoxin for decreasing operative time, difficulty, and pain of late second-trimester surgical abortions.

METHODS

We performed a randomized, double-masked, placebo-controlled trial of intra-amniotic digoxin for second-trimester dilation and evacuation (D&E) involving 126 consecutive women at an inner-city public hospital. Eligible women had gestational ages of 20-23.1 weeks, spoke English or Spanish, and were at least 16 years old. Digoxin (1 mg) or saline was injected intra-amniotically 24 hours before the procedure, at cervical laminaria insertion. The primary outcome was procedure duration. Sample size was based on 80% power to detect a difference of 3.5 minutes between groups.

RESULTS

The two groups were similar in demographic factors, obstetric histories, and gestational duration. The average gestational length was 22.5 weeks. There was no difference in procedure duration (mean +/- standard deviation) between groups (placebo 14.7 +/- 7.0, digoxin 15.4 +/- 8.0). There were no differences in blood loss estimated by surgeons, pain scores, procedure difficulty scores, or complications between groups. Vomiting was significantly more common in those who received digoxin (placebo 3.1%, digoxin 16.1%). Most subjects (91%) reported that they preferred their fetuses were dead before the abortions.

CONCLUSION

Although digoxin did not increase efficacy of late second-trimester abortion, patient preference might justify its use.

Vaccine-induced antibodies inhibit CETP activity in vivo and reduce aortic lesions in a rabbit model of atherosclerosis

Using a vaccine approach, we immunized New Zealand White rabbits with a peptide containing a region of cholesteryl ester transfer protein (CETP) known to be required for neutral lipid transfer function. These rabbits had significantly reduced plasma CETP activity and an altered lipoprotein profile. In a cholesterol-fed rabbit model of atherosclerosis, the fraction of plasma cholesterol in HDL was 42% higher and the fraction of plasma cholesterol in LDL was 24% lower in the CETP-vaccinated group than in the control-vaccinated group. Moreover, the percentage of the aorta surface exhibiting atherosclerotic lesion was 39.6% smaller in the CETP-vaccinated rabbits than in controls. The data reported here demonstrate that CETP activity can be reduced in vivo by vaccination with a peptide derived from CETP and support the concept that inhibition of CETP activity in vivo can be antiatherogenic. In addition, these studies suggest that vaccination against a self-antigen is a viable therapeutic strategy for disease management.

Safety of intra-amniotic digoxin administration before late second-trimester abortion by dilation and evacuation

OBJECTIVE

The purpose of this study was to determine the safety of intra-amniotic digoxin injection before late second-trimester pregnancy termination by dilation and evacuation through an assessment of maternal systemic digoxin absorption, cardiac rhythm, and coagulation parameters.

STUDY DESIGN

Pregnant women at between 19 and 23 weeks' gestation received 1.0 mg digoxin through intra-amniotic injection and then had serum digoxin levels determined for 48 hours and Holter cardiac monitoring performed for 24 hours. Clotting parameters were assessed before digoxin injection and 24 hours later, at the time of the dilation and evacuation procedure.

RESULTS

Eight patients completed the study. The mean (+/-SD) serum digoxin peak concentration was 0.81 +/- 0.22 microg/L (range, 0.5-1.1 microg/L). The mean (+/-SD) time to peak digoxin concentration was 11.0 +/- 5.55 hours (range, 4-20 hours). Ambulatory cardiac monitoring showed no rhythm or conduction abnormalities associated with digoxin. Prothrombin time, partial thromboplastin time, and fibrinogen levels did not change significantly between determinations before and after the dilation and evacuation procedure (11.5 to 11.4 seconds, 24.1 to 24.4 seconds, and 441 to 475 mg/dL, respectively).

CONCLUSION

The maximum digoxin concentration peak achieved after intra-amniotic injection was in the low therapeutic range. No rhythm or conduction abnormalities associated with digoxin were noted by Holter monitoring. Coagulation parameters did not change significantly. On the basis of the limited systemic absorption and the absence of clinically significant cardiac or clotting effects, intra-amniotically administered digoxin may be considered safe for use before late second-trimester pregnancy terminations.

Characterization of N-linked oligosaccharides bearing sialyl lewis x moieties on an alternatively glycosylated form of soluble complement receptor type 1 (sCR1)

We sought to produce a complement inhibitory protein possessing oligosaccharides specifically modified to contain the sialyl Lewis x (sLe(x)) moiety. This modified glycoprotein could combine anti-complement activity with the ability to inhibit selectin-mediated interactions and concentrate this activity to sites of activated endothelium where selectins are upregulated. Soluble complement receptor type 1 (sCR1), previously shown to be effective in inhibiting the complement cascade, was produced in a cell line capable of adding fucose to N-linked oligosaccharides in the alpha1-3 linkage, which is necessary for sLe(x) glycosylation. The glycoprotein purified from these cells was designated sCR1sLe(x), and may prove to be more effective than sCR1 in some clinical applications. Detailed analysis and characterization of sCR1sLe(x) was performed to confirm that the N-linked oligosaccharides possessed sLe(x) moieties and also to determine the extent of sLe(x) glycosylation. The glycoproteins were characterized by oligosaccharide profiling, sequencing, linkage analysis and quantified by differential enzymic digestion, using fluorophore-assisted carbohydrate electrophoresis. The major glycans were identified as biantennary oligosaccharides (including sialylated and non-core fucosylated glycans). The linkages of sialic acid and the branched fucose were analysed by digestion with linkage-specific enzymes and subsequent separation by electrophoresis. All data were consistent with the presence of sLe(x) moieties on the N-linked oligosaccharides of sCR1sLe(x). sCR1sLe(x) is a prime example of a recombinant protein expressed with oligosaccharides engineered for a specific biological function, and produced using a commercially viable method.

Recombinant glycoproteins that inhibit complement activation and also bind the selectin adhesion molecules

Soluble human complement receptor type 1 (sCR1, TP10) has been expressed in Chinese hamster ovary (CHO) DUKX-B11 cells and shown to inhibit the classical and alternative complement pathways in vitro and in vivo. A truncated version of sCR1 lacking the long homologous repeat-A domain (LHR-A) containing the C4b binding site has similarly been expressed and designated sCR1[desLHR-A]. sCR1[desLHR-A] was shown to be a selective inhibitor of the alternative complement pathway in vitro and to function in vivo. In this study, sCR1 and sCR1[desLHR-A] were expressed in CHO LEC11 cells with an active alpha(1,3)-fucosyltransferase, which makes possible the biosynthesis of the sialyl-Lewisx (sLex) tetrasaccharide (NeuNAcalpha2-3Galbeta1-4(Fucalpha1-3)GlcNAc) during post-translational glycosylation. The resulting glycoproteins, designated sCR1sLex and sCR1[desLHR-A]sLex, respectively, retained the complement regulatory activities of their DUKX B11 counterparts, which lack alpha(1-3)-fucose. Carbohydrate analysis of purified sCR1sLex and sCR1[desLHR-A]sLex indicated an average incorporation of 10 and 8 mol of sLex/mol of glycoprotein, respectively. sLex is a carbohydrate ligand for the selectin adhesion molecules. sCR1sLex was shown to specifically bind CHO cells expressing cell surface E-selectin. sCR1[desLHR-A]sLex inhibited the binding of the monocytic cell line U937 to human aortic endothelial cells, which had been activated with tumor necrosis factor-alpha to up-regulate the expression of E-selectin. sCR1sLex inhibited the binding of U937 cells to surface-adsorbed P-selectin-IgG. sCR1sLex and sCR1[desLHR-A]sLex have thus demonstrated both complement regulatory activity and the capacity to bind selectins and to inhibit selectin-mediated cell adhesion in vitro.

Endothelial targeting and enhanced antiinflammatory effects of complement inhibitors possessing sialyl Lewisx moieties

The complement inhibitor soluble complement receptor type 1 (sCR1) and a truncated form of sCR1, sCR1[desLHR-A], have been generated with expression of the selectin-reactive oligosaccharide moiety, sialyl Lewisx (sLex), as N-linked oligosaccharide adducts. These modified proteins, sCR1sLex and sCR1[desLHR-A]sLex, were assessed in the L-selectin- and P-selectin-dependent rat model of lung injury following systemic activation of complement by cobra venom factor and in the L-selectin-, P-selectin-, and E-selectin-dependent model of lung injury following intrapulmonary deposition of IgG immune complexes. In the cobra venom factor model, sCR1sLex and sCR1[desLHR-A]sLex caused substantially greater reductions in neutrophil accumulation and in albumin extravasation in lung when compared with the non-sLex-decorated forms. In this model, increased lung vascular binding of sCR1sLex and sCR1[desLHR-A]sLex occurred in a P-selectin-dependent manner, in contrast to the absence of any increased binding of sCR1 or sCR1[desLHR-A]. In the IgG immune complex model, sCR1[desLHR-A]sLex possessed greater protective effects relative to sCR1[desLHR-A], based on albumin extravasation and neutrophil accumulation. Enhanced protective effects correlated with greater lung vascular binding of sCR1[desLHR-A]sLex as compared with the non-sLex-decorated form. In TNF-alpha-activated HUVEC, substantial in vitro binding occurred with sCR1[desLHR-A]sLex (but not with sCR1[desLHR-A]). This endothelial cell binding was blocked by anti-E-selectin but not by anti-P-selectin. These data suggest that sLex-decorated complement inhibitors have enhanced antiinflammatory effects and appear to have enhanced ability to localize to the activated vascular endothelium.

Filter matrix estimation in automated DNA sequencing

In four-color fluourescence-based automated DNA sequencing, a 4 x 4 filter matrix parameterizes the relationship between the dye-intensity signals of interest and the data collected by an optical imaging system. The filter matrix is important because the estimated DNA sequence is based on the dye intensities that can only be recovered via inversion of the matrix. In this paper, we present a calibration method for the estimation of the columns of this matrix, using data generated through a special experiment in which DNA samples are labeled with only one fluorescent dye at a time. Simulations and applications of the method to real data are provided, with promising results.

A method to determine the filter matrix in four-dye fluorescence-based DNA sequencing

In a previous paper (Yin et al., Electrophoresis 1996, 17, 1143-1150), an automated method for matrix determination in four-dye fluorescence-based DNA sequencing was presented. As a continuation of that work, we have developed an alternative method to estimate the matrix from raw sequence data. The method uses an iterative clustering technique to associate each 4 x 1 data vector with one column of the desired filter matrix, using Kullback's I-divergence as a distance measure. The method requires less preprocessing of the data and less computation than the approach described by Yin et al. (Electrophoresis 1996, 17, 1143-1150). An example demonstrating applicability of the proposed method to Applied Biosystems sequencer data is given.

Artifacts in computational optical-sectioning microscopy

We tested the most complete optical model available for computational optical-sectioning microscopy and obtained four main results. First, we observed good agreement between experimental and theoretical point-spread functions (PSF's) under a variety of imaging conditions. Second, using these PSF's, we found that a linear restoration method yielded reconstructed images of a well-defined phantom object (a 10-microns-diameter fluorescent bead) that closely resembled the theoretically determined, best-possible linear reconstruction of the object. Third, this best linear reconstruction suffered from a (to our knowledge) previously undescribed artifactual axial elongation whose principal cause was not increased axial blur but rather the conical shape of the null space intrinsic to nonconfocal three-dimensional (3D) microscopy. Fourth, when 10-microns phantom beads were embedded at different depths in a transparent medium, reconstructed bead images were progressively degraded with depth unless they were reconstructed with use of a PSF determined at the bead's depth. We conclude that (1) the optical model for optical sectioning is reasonably accurate; (2) if PSF shift variance cannot be avoided by adjustment of the optics, then reconstruction methods must be modified to account for this effect; and (3) alternative microscopical or nonlinear algorithmic approaches are required for overcoming artifacts imposed by the missing cone of frequencies that is intrinsic to nonconfocal 3D microscopy.

Shoulder dystocia: an analysis of risks and obstetric maneuvers

OBJECTIVE

The purpose of this study was to determine whether there is a risk profile for predicting or preventing shoulder dystocia and whether any of the obstetric maneuvers to disimpact a shoulder reduce the likelihood of permanent injury.

STUDY DESIGN

A retrospective analysis of 14,297 parturients with 12,532 vaginal deliveries and 1765 cesarean sections (12.4%) from January 1986 through June 1990 was performed. A total of 204 maternal and infant charts, related to shoulder dystocia or neonatal injury, were reviewed in depth for age, parity, episiotomy, type of delivery, hemorrhage, maternal obesity, diabetes, weight gain, fetal weight, sex, and Apgar scores. In addition, the type of maneuver or combination thereof used to relieve the dystocia, type of injury to the infant, and follow-up of the injury were reviewed.

RESULTS

The 185 coded episodes of shoulder dystocia represent 1.4% of all vaginal deliveries (12,532). There were 42 injuries recorded: 14 fractured clavicles and 28 brachial plexus injuries. An additional 19 patients, not coded for shoulder dystocia, sustained 14 fractured clavicles and five brachial plexus injuries. All but one of the brachial plexus injuries resolved by 6 months. The occurrence of shoulder dystocia increased in direct relationship to the birth weight and becomes significant in newborns over 4000 gm (p < 0.01). The occurrence of a previous large infant was also a significant risk factor (p < 0.01). Diabetes and midforceps delivery become significant factors only in the presence of a large fetus. Obesity, multiparity, postdate pregnancy, use of oxytocin, low forceps delivery, episiotomy, and type of anesthesia were unrelated to shoulder dystocia. No delivery method was without injury.

CONCLUSIONS

This study clearly indicates that most of the traditional risk factors for shoulder dystocia have no predictive value, shoulder dystocia itself is an unpredictable event, and infants at risk for permanent injury are virtually impossible to predict. In addition, no delivery method in shoulder dystocia was superior to another with respect to injury. Thus no protocol should serve to substitute for clinical judgment.

Analytical comparison of sensor signal processing enhancements for NDT synthetic aperture ultrasonic imaging

The results of a detailed analytical study of the effects of sensor processing techniques on clutter suppression and image enhancement for nondestructive testing (NDT) systems are presented. A relatively simple beamforming/diffraction model is developed for near-field, wideband, synthetic aperture ultrasonic imaging in NDT systems. The physical model is used to quantitatively evaluate a variety of front-end sensor signal processing tradeoffs for the enhanced detection and sizing of defects. It is shown using statistical microscopic scattering calculations that a combination of increased spatial sampling and rectangular windowing can increase the signal-to-clutter ratio by ~10 dB while maintaining crack size resolutions well below future projected specifications. The sensor signal processing image enhancements are demonstrated by the construction of simulated strip-map SAFT (synthetic aperture focusing technique) images of metallic crack defects in the presence of large numbers of randomly distributed clutter (simulated grain boundary) scatterers.

A graphical user interface for quantitative imaging and analysis of electrophoretic gels and autoradiograms

DNA/GUI (DNA Graphical User Interface) is an interactive software system for rapid and efficient analysis of images of the types used in genome mapping, such as autoradiograms and electrophoretic gels. Images are digitized using a commercially available charge-coupled-device (CCD) camera system and analyzed on a graphics workstation using a menu-driven user interface. DNA/GUI features automatic lane and band detection, simultaneous display of multiple images and a unique spatial-normalization algorithm. Images and their associated data are archived and easily available for later recall. Preliminary results indicate that DNA/GUI is a useful tool in the analysis and comparison of images used in a variety of applications such as genetic-linkage analysis and DNA restriction mapping. The interactive display software is based on the X Window System and is therefore readily portable to a variety of graphics workstations.

Biosynthesis of phosphatidylinositol-glycan (PI-G)-anchored membrane proteins in cell-free systems: PI-G is an obligatory cosubstrate for COOH-terminal processing of nascent proteins

It is generally recognized that nascent proteins destined to be processed to a phosphatidylinositol-glycan (PI-G)-anchored membrane form contain a hydrophobic signal peptide at both their NH2 and COOH termini. In previous studies we showed that rough microsomal membranes (RM) prepared from CHO cells can carry out COOH-terminal processing. We have now investigated RM prepared from many additional cell types, including frog oocytes, B cells, and T cells, and found that all are competent with respect to COOH-terminal processing. Exceptions were certain mutant T cells that had been shown to be defective at various steps of PI-G anchor biosynthesis [Sugiyama, E., De Gasperi, R., Urakaze, M., Chang, H.-M., Thomas, L. J., Hyman, R., Warren, C. D. & Yeh, E. T. H. (1991) J. Biol. Chem. 266, 12119-12122]. In one such defective mutant, COOH-terminal processing activity of RM could be restored either by transfecting the intact cells with the gene for the deficient step in PI-G synthesis or by adding PI-G extracts to the RM in vitro. Cleavage of the COOH-terminal signal peptide in the RM is therefore dependent on the presence of intact PI-G incorporated into the mature protein.

Differential expression of glycosylphosphatidylinositol-anchored proteins in a murine T cell hybridoma mutant producing limiting amounts of the glycolipid core. Implications for paroxysmal nocturnal hemoglobinuria

A T cell hybridoma mutant, which expressed a markedly reduced level of glycosylphosphatidylinositol (GPI)-anchored proteins on the cell surface, was characterized. The surface expression level of Thy-1 was approximately 17% of the wild-type level, whereas the surface expression of Ly-6A was approximately 2.4% of the wild-type level. We show here that these cells synthesized limiting amounts of the GPI core and that the underlying defect in these cells was an inability to synthesize dolichyl phosphate mannose (Dol-P-Man) at the normal level. The defect in Ly-6A expression could be partially corrected by tunicamycin, which blocked the biosynthesis of N-linked oligosaccharide precursors and shunted Dol-P-Man to the GPI pathway. Full restoration of Thy-1 and Ly-6A expression, however, required the stable transfection of a yeast Dol-P-Man synthase gene into the mutants. These results revealed that when the GPI core is limiting, there is a differential transfer of the available GPI core to proteins that contain GPI-anchor attachment sequences. Our findings also have implications for the elucidation of the defects in paroxysmal nocturnal hemoglobinuria.

Efficient synthetic aperture imaging from a circular aperture with possible application to catheter-based imaging

Phased-array imaging, including complete dynamic focus, is explored for imaging using a circular aperture. Based on the constraints of catheter-based systems, an efficient synthetic aperture method has been developed for imaging using a single wire connection between the imaging array and external electronics. The method employs a highly sampled array with an element pitch small compared to the acoustic wavelength. On any given firing of the array, however, a large number of channels are electrically connected on both transmission and reception. From firing to firing, one element is dropped and one new element is included, in analogy to a classic linear array system. Using an optimal filtering approach for synthetic aperture reconstruction, a dynamically focused image exhibiting diffraction limited resolution is produced. The results of detailed simulations are presented demonstrating the capabilities of the method. In addition, the prospects for real-time implementation of the reconstruction are discussed.

A personal computer based implementation of the maximum-likelihood method of analysis of electron microscope autoradiographs

The maximum-likelihood (ML) method for the quantitative analysis of electron-microscopic autoradiographs has been shown to be substantially superior to the conventional crossfire (CF) method. It can generate reliable and accurate tracer concentration estimates with far fewer micrographs and produce valid estimates even at counts low enough to preclude the use of the crossfire method while eliminating the need for special ad hoc treatment of narrow membranous structures as well as the secondary verification of the tracer concentration estimates. Despite these significant advantages, the large computational requirements of the ML method has to date hampered its widespread use. In this paper, we present a new line-integration method that allows us to reduce the computational requirements of the ML method to a point where it becomes feasible to implement it on a small computer system of the type typically available to a laboratory user of EM autoradiography. We present the complete line-integration method for the particular case of EM autoradiography with tritium, and show how it can be adapted to other isotopes. We have constructed a software package that implements the complete maximum-likelihood method on the IBM PC class of machines using our line-integration method. Features of this software package which are of particular importance to the research community are device independence, which makes it usable with a large variety of currently available laboratory equipment, and easy portability of the software and data between different computer systems.

Functional analysis of T-cell mutants defective in the biosynthesis of glycosylphosphatidylinositol anchor. Relative importance of glycosylphosphatidylinositol anchor versus N-linked glycosylation in T-cell activation

The glycosylphosphatidylinositol (GPI) anchor, potentially capable of generating a number of second messengers, such as diacylglycerol, phosphatidic acid, and inositol phosphate glycan, has been postulated to be involved in signal transduction in various cell types, including T-cells. We have identified a panel of T-cell hybridoma mutants that are defective at various steps of GPI anchor biosynthesis. Since they were derived from a functional T-T hybridoma, we were able to determine the precise role of the GPI anchor in T-cell activation. Two mutants were chosen for this analysis. The first mutant is defective at the first step of GPI anchor biosynthesis, i.e. in the transfer of N-acetylglucosamine to a phosphatidylinositol acceptor. Thus, it cannot form any GPI precursors or GPI-like compounds. Interestingly, this mutant can be activated by antigen, superantigen, and concanavalin A in a manner comparable to the wild-type hybridoma. These data strongly suggest that the GPI anchor, its precursor, or its potential cleavage product, inositol phosphate glycan, is not required for the early phase of T-cell activation. The second mutant is able to synthesize the first two GPI precursors, but is not able to add mannose residues to them due to a deficiency in dolichol-phosphate-mannose (Dol-P-Man) biosynthesis. Unexpectedly, all of the Dol-P-Man mutants are defective in activation by antigen, suprantigen, and concanavalin A despite normal T-cell receptor expression. Here, we show that the activation defect was due to a pleiotropic glycosylation abnormality because Dol-P-Man is required for both GPI anchor and N-linked oligosaccharide biosynthesis. When the yeast Dol-P-Man synthase gene was stably transfected into the mutants, full expression of surface GPI-anchored proteins was restored. However, N-linked glycosylation was either partially or completely corrected in different transfectants. Reconstitution of activation defects correlates well with the status of N-linked glycosylation, but not with the expression of GPI-anchored proteins. These results thus reveal an unexpected role of N-linked glycosylation in T-cell activation.

Identification of defects in glycosylphosphatidylinositol anchor biosynthesis in the Thy-1 expression mutants

A number of eukaryotic proteins are anchored to the membrane by glycosylphosphatidylinositol (GPI), of which the core structure is conserved from protozoan to mammalian cells. Here, we used a panel of thymoma mutants, which synthesize Thy-1 but cannot express it on the cell surface, to study the GPI biosynthetic pathway in mammalian cells. These mutants have been assigned into six complementation classes (A, B, C, E, F, H) by the technique of somatic cell hybridization. Using a combination of metabolic labeling and chemical/enzymatic tests, the biosynthetic defects were mapped to four different steps. Class A, C, and H mutants cannot transfer N-acetylglucosamine (GlcNAc) to a phosphatidylinositol acceptor, suggesting that the first step of GPI synthesis is regulated by at least three genes. The Class E mutant does not synthesize dolichol-phosphate-mannose, the donor for the first mannose residue transferred to the GPI core, and thus cannot form any mannose-containing GPI precursors. Class B and F mutants are defective in the addition of the third mannose residue or ethanolamine phosphate, respectively, to the elongating GPI core. Our findings have implications for the biosynthesis and attachment of the mammalian GPI anchor.

Correction of a defect in mammalian GPI anchor biosynthesis by a transfected yeast gene

Glycosylphosphatidylinositol (GPI) serves as a membrane anchor for a large number of eukaryotic proteins. A genetic approach was used to investigate the biosynthesis of GPI anchor precursors in mammalian cells. T cell hybridoma mutants that cannot synthesize dolichol-phosphate-mannose (Dol-P-Man) also do not express on their surface GPI-anchored proteins such as Thy-1 and Ly-6A. These mutants cannot form mannose-containing GPI precursors. Transfection with the yeast Dol-P-Man synthase gene rescues the synthesis of both Dol-P-Man and mannose-containing GPI precursors, as well as the surface expression of Thy-1 and Ly-6A, suggesting that Dol-P-Man is the donor of at least one mannose residue in the GPI core.

The relation of diabetic control to in vivo pH of soft tissue abscesses

It has been shown that induced soft tissue abscesses have a lower intra-abscess pH in the uncontrolled diabetic host than in the nondiabetic control. These differences were felt to be secondary to alterations in white cell metabolism. The current study compares the intra-abscess pH in three groups of mice: (I) nondiabetic, (II) untreated diabetic, and (III) insulin-treated diabetic. Diabetes was induced with streptozotocin in male white mice. The bacteria used to induce the abscesses were a combination of B. fragilis and Enterococcus. The blood glucose values of groups I, II, and III were 189 mg% (+/- 20.3), 256 mg% (+/- 121.9), and 712.8 mg% (+/- 169.7), respectively. None of the animals were ketotic, and peritoneal pH (reflecting systemic pH) showed no significant differences between groups. There were no significant differences in colony counts between any groups. The intra-abscess pH values of groups I, II, and III were 6.97 (+/- 0.26), 6.85 (+/- 0.41), and 6.08 (+/- 0.70). The differences in intra-abscess pH and blood glucose levels were all significantly different from each other when all three groups were compared. The insulin-treated mice tended to return to normality but had the widest spread of values. Since a decrease in intra-abscess pH has been felt to be a reflection of white cell activity, our studies may be the first to demonstrate an in vivo effect of insulin on white cell activity.

Spatial normalization of one-dimensional electrophoretic gel images

A strategy for using processed, digitized images of one-dimensional electrophoretic gels to facilitate the analysis of large sets of overlapping clones is described. The images are acquired from fluorescently stained gels or from transilluminated gel photographs using a cooled, solid-state charge-coupled device camera. By employing sets of bands in the size-standard lanes as reference points, all the gel images are spatially normalized to a common reference template. After normalization, lane images from different gels can be compared as though the gels had been electrophoresed under identical, uniform-field conditions. Applications of this procedure to the analysis of a large set of overlapping lambda clones from chromosome VII of Saccharomyces cerevisiae and to the estimation of fragment sizes are illustrated.

Time-dependent cleavage of a high-mannose form of Ii to p25 in an intracellular compartment

The cleavage of a high-mannose form of Ii to p25 was demonstrated in an intracellular compartment of B cells. Subcellular fractions of 72 hr-activated B cells, separated by Percoll density gradient centrifugation, were immunoprecipitated with anti-class II or anti-Ii serum and characterized for 5'-nucleotidase, acid phosphatase, and radiolabeled transferrin. The cleavage of p25 from Ii as a C-terminal fragment occurred from 20 to 60 min after synthesis in an intracellular compartment which was intermediate in density between lysosomal and plasma membrane fractions and coincided with the lighter to two internalized transferrin compartments. Chloroquine or monensin treatments, at maximal nontoxic doses, which block Golgi and lysosomal functions, did not seem to alter the cleavage of Ii to p25. p25 molecules were reduced to about 10,500 daltons by treatment with endoglycosidases F or H. We conclude that p25 was generated from a high mannose form of Ii in the endoplasmic reticulum or cis-Golgi. This finding could either implicate that site for class II MHC desetope charging with foreign peptides or reflect a mechanism for degradation of "excess" Ii molecules.

In vivo pH of induced soft-tissue abscesses in diabetic and nondiabetic mice

Infections in the diabetic host have been shown to persist longer than those in the nondiabetic host. To investigate whether intra-abscess milieu might be a contributing factor to this persistence, the in vivo intra-abscess pH was measured in induced soft-tissue abscesses in diabetic and nondiabetic mice. Two models (female genetically obese insulin-resistant and male streptozocin-induced diabetic mice) were used with appropriate controls. The bacteria injected to produce the soft-tissue abscesses were Bacteroides fragilis and Enterococcus (B + E), Staphylococcus epidermidis and Enterococcus (S + E), and S. aureus (SA). Intra-abscess pH measured on day 3 was consistently and significantly lower in all diabetic mice compared with their controls. In the diabetic mice, the pH of an abscess induced with B + E, S + E, and SA was 6.28 (n = 17), 6.79 (n = 10), and 6.52 (n = 10), respectively; the pH in the controls was 7.21 (n = 20), 7.30 (n = 10), and 7.17 (n = 10), respectively. Differences in all groups between diabetic and nondiabetic mice were significant. The blood glucose values of the diabetic mice averaged 722 mg/dl, and in the nondiabetic mice were 210 mg/dl. No animals were ketotic. There were no significant differences in total colony counts between any groups. In conclusion, there is a significantly lower pH in the abscess of the diabetic host compared with the nondiabetic host that is not related to the numbers or types of causative bacteria.

Quantitative real-time imaging of myocardium based on ultrasonic integrated backscatter

The integrated backscatter calculation over the full, two-dimensional echocardiographic sector is implemented to produce images from closed-chest dogs. This new real-time integrated backscatter measurement system allows a continuous determination of integrated backscatter from all myocardial regions in the ultrasonic view. By replacing the conventional video processor in a commercial two-dimensional echocardiographic imager with this new real-time backscatter measurement system, it is possible to produce real-time two-dimensional images based on integrated backscatter.